title: The interaction between smoking and Epstein-Barr virus as multiple sclerosis risk factors may depend on age.
abstract: The multiple sclerosis (MS) risk factors smoking and remote Epstein-Barr virus (EBV) infection have been suggested to interact statistically, but the results are conflicting. In a prospective study on 192 MS cases and 384 matched controls, we analysed levels of cotinine as a marker of smoke exposure, and Epstein-Barr Nuclear Antigen-1 antibody reactivity. We assessed interaction on the additive and multiplicative scales, and estimated the effects of the risk factors across strata of each other. The results suggest that a negative interaction may be present in samples drawn at a young age, and a positive interaction among older subjects.
authors.affiliation: Department of Pharmacology and Clinical Neuroscience, Section of Neurology at Umeå University, Umeå, Sweden.
authors.forename: Jonatan
authors.initials: J
authors.lastname: Salzer
authors.forename: Hans
authors.initials: H
authors.lastname: Stenlund
authors.forename: Peter
authors.initials: P
authors.lastname: Sundström
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000097:blood; D020031:Epstein-Barr Virus Infections / Q000276:immunology*; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000276:immunology*; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000276:immunology*; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: Epstein-Barr virus; Multiple sclerosis; case control study; interaction; risk factors in epidemiology; smoking